Single-transmission telegraph system



W. A. CUSHING SINGLE TRANSMISSION TELEGRAPH SYSTEM Dec; 4, 1923. Q 1,475,987

Filed Jan. 27. 1919 I INVEIYTOR. Wflbiaslm g I 4 ATTORNEY Patented Dec. 4, 1923.

UHTED s'rrs v I 1,475,9 7 Afi N'E orrics;

WILLIAM A. CUSHING, OF NEIVIB URG HEIGHTS, OHIO, ASSIGNOR TO AMERICAN TELE- PHONE AND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK.

SINGLE-TRANSMISSION TELEGRAPH SYSTEM.

Application filed Janu ary 27, 1919; Serial No. 273,370.

To all whom it ma concern:

Be 'it'kno'wn that I,"WILLIA A. CUSH- ING, residing at 4053 East th-St, Newburg Heights Village, in the county "of Cuyahoga and State of Ohio, have invented certain Improvements in Single-Transmis- 'sion Telegraph Systems, of which the follow ing isa specification. v 1

This invention relates to .signalingsystems and more particularly to arrangements for transmitting and receiving telegraph signals.

One of the principal objects of the invention is to provide a signaling arrangement which may be operated upon a single transmission basis, the signaling arrange ment being such that the signals are trans mitted by mea'ns'of a pole changing device and are received in a local circuit inductively related to the line, said local circuit being rendered inoperative when the pole changing device is transmitting signals.

The invention may now be more fully understood from the following description when read in connection with the accompanying drawing, Figures 1, 2and 3 of which constitute circuit diagrams of threedifierent modifications thereof.

Referring to Figure 1 which illustrates the principle of the invention, a line circuit L is shown, over which signals may be transmitted by the operation of a key K which controls the application of positive and negative battery to the line. A receiving means comprising a polar relay 1 is in- 'cluded in a local circuit 2 inductively related to the line L by means of av transformer 3. The polar relay 1 controls a local circuit including a sounder 4. When the key K is'operated in transmitting signals to the line L the circuit 2 of the polar relay 1 is opened at a local'contact 5 controlled by the key K so that the transmitted signals do not actuate the polar relay. When the transmiting key at the distant station is opened the direction of the current flowing over the line is changed and an impulse is produced in the circuit 2 which operates the polar relay to open the circuit of the sounder 4. When the distant key is closed an impulse in the reverse direction over the line induces an impulse in the reverse direction in the circuit 2, causing the polar relay 1 to again close the circuit of the sounder 4.

In Figures the invention is shown as applied to asystem in which the transmitting and receiv-ingset is located at a main station 'and'controlled from a loop running to I Y 'a loc'alstation. Inthis from of the inven tion the reversal of the polarity ofthe cur rent flow over the line is controlled by a pole changero of a'well-know'n form, said ole chan er com risin a main 0 eratin magnet I '7 and" an auxiliary controlling magnet 8. The main operating magnet is included in a local circuit 9, a sending key 10 of which is located at the main-station. The local circuit 9 is controlled by the contact of polar receiving relay 1, which is included in a circuit 2 inductively related to the line L by means of the transformer 3, and said circuit 9 includes a loop schematically indicated at 11, extending through keys and sounders at local stations. 7 -Received signals'operate the polar relay asdescribed in connection with the arrangement shownin Figure 1 to open and close the local circuit 9, to operate the sounders in the loop circuit. The magnet 7 of the pole changer 6 is deenergized each time the circuit 9 is opened by the polar relay 1, but said relay at the same time that it opens the circuit 9 also removes a short circuit 11 the magnet 7 of the pole changer 6 is deenergized and the magnet 8 of the pole changer remains short circuited so that the armature 12 of the pole changer is retracted to change the polarity of the current, flowing to the line L, thereby transmitting signals ,to a distant station. The pole changer 6 at the same time that it releases its armature in transmitting signals opens the local circuit of the polar receiving relay 1 at contact-5 so that said receiving circuit is unaffected by transmitted signals. In Figure 3 a circuit is shown illustrat ing the manner in which the invention may be applied to a telegraph repeater. In this figure, by operating the key 10 or a key in the loop 11, signals may be transmitted to I the same manner as in the'line L in exactly Figure 2. Signals transmitted from the line L, however, act inductively through the line L transformer 3 to operate the polar relayl ated, the auxiliary magnet 8; remains short, circ'uite'd so that the pole changer 6 releases its armature to transmit the signal to the V The pole change: 7: in repeating the signal opens the'local circuit of thepolar relay 1 at'contact 5', thereby preventing the repeated signal from actuating the polar relay. Signals arriving from the line L actuate thepolar relay "1 which'opens a circuit 9 without affecting the pole changer 6. The pole changer 6', however, 1s deener- .gized and retracts its armature to repeat the signal to the line L, at the same time opening the circuit of polar relay 1 at contact 5.

By means of this invention a simple and effective circuit for single transmission operation is provided, and wh le the lnv'entlon has been shown 111 what 1s considered its 'most desirable form it will be obvious that the general principlesherein disclosed; may

be embodied in many other organizations- 7 widely different from those illustrated with out departing from the spirit of the inven tion as defined in the following claims.

mitt-ing means,

What is claimed is: p p v 7 1. In a slgnallng system, a transmlsslon line, a receiving-means wlnductlvely related thereto, a pole changerfor transmitting signals tofsaid line, indicating means and transmitting means includedin' alocal 'circuit with saidi poley changer, said local circuit being under the control of said receiving means, means .to prevent said'pole changer from being actuated by said receivlng means, and :means to prevent said receiving means'from being actuated when said pole changer is actuated by said transc- 2. Ina signaling-system, transmission line sections, a repeater interconnecting said sections and comprising 1 two signaling sets, each set including a recelving means inducrtively associated with a corresp d ns section, a pole changer controlledby the re ceiving means of the opposite set, but unafiected by thereceiving means ofthe c0rre spending set, said, c-pole' changers being adapted to repeatto one line section signals inductively received from the other line sec;

tion, and means to render the receiving means of a'set inoperative when the pole changer of that set is repeating signals.

V ,In testimony'whereof, I have signed my name to this specification this17th day January, 1919. p a

' WILLIAM a. cUs-HING. 

